Compositions and methods of formulation for enteral formulas containing sialic acid

ABSTRACT

A nutritionally complete infant formula containing sialic acid derived from one or a number of nutritionally appropriate sources is described.

CROSS-REFERENCE TO RELATED PATENTS AND PATENT APPLICATION

This application is a continuation-in-part and claims the prioritybenefit of co-pending U.S. patent application Ser. No. 10/413,508, filedApr. 14, 2003, which is incorporated herein to the extent that it doesnot conflict with the disclosures of the present application.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates generally to infant's and children'snutritional formulas containing sialic acid and methods formanufacturing such formulas.

(2) Description of the Related Art

Sialic acid (N-acetylneuraminic acid or NANA) is a naturally occurringcomponent of human breast milk, where it is found associated withvarious oligosaccharides and glycoproteins. While human breast milkcontains substantial amounts of sialic acid, most infant formulascontain less than 25% of the sialic acid found in colostrum. Moreover,70% of the sialic acid in formulas is glycoprotein-bound, unlike humanbreast milk in which 75% of sialic acid is bound to oligosaccharides.See Heine, W., et al., Monatsschr Kinderheilkd 141:946-50 (1993), Wang,B., et al., Am J Clin Nutr 74:510-5 (2001), and Nakano, T., et al., ActaPaediatr Taiwan 42:11-17 (2001). Not surprisingly, the accumulation ofsialic acid by breast-fed infants is generally higher than forformula-fed infants. See Wang, B., et al., J Pediatr 138:914-6 (2001).Evidence suggests that sialic acid is important in the development andfunction of the neonatal brain where it is a major component ofgangliosides. See Carlson, S.E., Am J Clin Nutr 41:720-6 (1985), Morgan,B. and Winnick, M., J Nutr 110:416-24 (1980), Svennerholm, L., et al.,Biochim Biophys Acta 1005:109-17 (1989), and Wang, B., et al., CompBiochem Physiol A Mol Integr Physiol 435-9 (1998).

Cow's milk-based formulas generally have low sialic acid content. In onestudy, the concentration of sialic acid in several casein/wheycombination formulas was less than 200 mg sialic acid/L. Moreover, soyprotein-based formulas contain substantially reduced levels of sialicacid as compared to cow's milk-based formula. Therefore, formulas thatare both lactose free and soy protein-based would exhibit very lowsialic acid content.

There are several known sources of sialic acid in its various conjugatedforms. These include, but are not limited to, free N-acetylneuraminicacid (or sialic acid), the oligosaccharide sialyllactose, sialicacid-containing gangliosides, and the protein casein macropeptide (CMP),also referred to as glycomacropeptide (GMP), andcaseinoglycomacropeptide (cGMP).

The addition of sialic acid or sources of sialic acid to certainnutritional formulas has been mentioned in the art. For example, U.S.Pat. No. 6,506,422 discloses a particular nutritional formula containingcasein glycomacropeptide and complimentary essential amino acids otherthan phenylalanine for administration to patients suffering fromphenylketonuria. The levels of sialic acid found in infant formulas arenot mentioned.

U.S. Pat. No.6,270,827, discloses a formulation containing human milkproteins or recombinant host resistance factors, one of which isrecombinant human kappa-casein, to supplement synthetic infant formulas.

U.S. Pat. No. 4,762,822 discloses the use of N-acetylneuraminic acid organgliosides containing sialic acid in infant formula to protect thenewborn from gastrointestinal disease-producing organisms.

International patent application WO 01/60346 A2 discloses a nutritionalformulation containing the oligosaccharides oligofructose andsialyllactose as prebiotic substances to promote the growth ofbifidobacteria in the gut that may be used in conjunction with infantformula.

While the use of sialic acid and sialic acid sources in infant formulais mentioned in the prior art, it would be useful to provide an infantformula having enhanced amounts of sialic acid similar to breast milk,and in particular, to provide infant formula that is nutritionallycomplete. Furthermore, it would be useful to provide infant formulahaving enhanced amounts of sialic acid while also providing an aminoacid profile that is similar to breast milk.

SUMMARY OF THE INVENTION

Briefly, the present invention is directed to a novel infant formulacomprising a cGMP having an enhanced concentration of sialic acid.

The present invention is also directed to a novel infant formulacomprising a cGMP having an enhanced concentration of sialic acid and areduced level of threonine.

The present invention is also directed to a novel method of producing aninfant formula comprising intermixing a cGMP having an enhancedconcentration of sialic acid with sources of protein, carbohydrate andlipid sufficient to provide a nutritionally complete formula.

Accordingly, it has been found that the present invention provides aninfant formula having enhanced amounts of sialic acid similar to breastmilk, and in particular, an infant formula that is nutritionallycomplete, and also provides an infant formula having enhanced amounts ofsialic acid while also providing an amino acid profile that is similarto breast milk, and in particular, an infant formula having a reducedthreonine content.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference now will be made in detail to the embodiments of theinvention, one or more examples of which are set forth below. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used on another embodiment to yield a stillfurther embodiment.

Thus, it is intended that the present invention cover such modificationsand variations as come within the scope of the appended claims and theirequivalents. Other objects, features and aspects of the presentinvention are disclosed in or are obvious from the following detaileddescription. It is to be understood by one of ordinary skill in the artthat the present discussion is a description of exemplary embodimentsonly, and is not intended as limiting the broader aspects of the presentinvention.

It has been found that certain cGMP-based products having enhancedlevels of sialic acid can be used to produce infant formula having anenhanced content of sialic acid. These formulas are suitable to supportnormal growth and development of infants and children. Specifically, thenovel formulas include one or a combination of nutritionally appropriatesource(s) of sialic acid having enhanced levels of sialic acid. Thelevel of sialic acid in the formula is designed to mimic the totalsialic acid found in breast milk over the period of 0-12 months oflactation.

Certain of the innovative aspects of the invention involve the use ofnovel cGMP-based products that contain levels of sialic acid that arehigher than normally found in cGMP products that are now commerciallyavailable. These novel products can be used alone or in combination toachieve sialic acid levels that mimic that found in breast milk, basedon the sialic acid content of the various source ingredients.

This invention is directed to a composition and a method of formulatingmilk protein-based formulas, both with and without lactose,non-milk-based formulas, including soy protein-based formulas, aminoacid formulas, and rice protein formulas, that contain sialic acid atconcentrations comparable to that found in human milk. The nature andnovelty of the invention involves the appropriate selection of sialicacid-containing ingredients to achieve both appropriate sialic acidlevels as well as appropriate nutrients for specific infant andchildren's formulas.

For example, in cow's milk protein-based formulas that contain lactose,the supplemental sialic acid in this composition may come from one or acombination of sources, particularly free sialic acid (neuraminic acid),3′-sialyllactose, 6′-sialyllactose, or other sialic acid-containingoligosaccharide, and casein glycomacropeptide (cGMP) or other sialicacid-containing milk protein fraction, including whey protein. Thesialyllactose conjugate(s) used in this invention may replace a portionof the lactose customarily used in these formulations, while the caseinglycomacropeptide (cGMP) and other milk protein fractions may replace aportion of the protein fraction of the formula. In the case oflactose-free formulas, which are also milk protein-free, free sialicacid, other non-cow's milk protein fractions containing sialic acid, orsialic acid-containing oligosaccharides other than lactose may be used.The fat, vitamin, and mineral concentrations of these compositions areotherwise nutritionally appropriate for infants. The total concentrationof sialic acid in these formulations would mimic that found in breastmilk and may typically be within a range of about 250 mg/L (as found inmature human breast milk) to about 1500 mg/L (as found in humancolostrums).

The present invention provides a nutritionally complete formulation thatincludes one or more sources of sialic acid, in amounts which mimic theconcentration of sialic acid found in human breast milk. The presentinvention additionally provides a method of making such formulations, inthe form of milk protein-based formulas, both with and without lactose,non-milk-based formulas, including soy protein-based formulas, aminoacid formulas, and rice protein formulas.

The form of administration of and incorporation of sialic acid in themethod of the present invention is not critical, as long as an effectiveamount is administered. A convenient form of administration is to addsialic acid to an infant formula (including those for both term andpreterm infants), follow-on formula, toddler's beverage, milk, yogurt,or fermented product. Alternatively, sialic acid can be administered asa supplement that is not part of a formula feeding such as, for example,drops, sachets or combinations with other nutrients such as vitamins.Sialic acid can be also added to other nutrients suitable for feeding toyoung children such as, for example, solid baby food, fruit juices,gelatines, cookies, candies, etc. Other examples of administering sialicacid in nutrients can be developed by a person with ordinary skill inthe art of infant and child nutrition. All these forms of sialic acidadministration, as well as others, are within the scope of the presentinvention.

In one embodiment of the invention, sialic acid is administered as partof an infant formula. The infant formula for use in the presentinvention is, typically, nutritionally complete and contains suitabletypes and amounts of lipids, carbohydrates, proteins, vitamins andminerals. The amount of lipids or fats typically can vary from about 3to about 7 g/100 kcal. The amount of proteins typically can vary fromabout 1 to about 5 g/100 kcal. The amount of carbohydrates typically canvary from about 6 to about 16 g/100 kcal. Protein sources can be anyused in the art, and may include, for example, nonfat milk, wheyprotein, casein, soy protein, hydrolyzed protein, and amino acids. Lipidsources can be any used in the art such as, for example, vegetable oilssuch as palm oil, soybean oil, palm olein oil, corn oil, canola oil,coconut oil, medium chain triglyceride oils, high oleic sunflower oil,and high oleic safflower oil. Carbohydrate sources can be any known inthe art such as, for example, lactose, glucose polymers, corn syrupsolids, maltodextrins, sucrose, starch, and rice syrup solids.

The present invention is also directed to a novel method of producing aninfant formula comprising intermixing a cGMP having an enhancedconcentration of sialic acid with sources of protein, carbohydrate andlipid sufficient to provide a nutritionally complete formula. Thehigh-sialic acid cGMP can be any of such products that are discussedherein, and the sources or protein, carbohydrate and lipid, along withany other useful and desirable components that are normally found ininfant formulas, are well known in the art.

Conveniently, several commercially available infant formulas can be usedas the basic formula for the sialic acid or sialic acid-sourcesadditions. For example, Enfamil® Lipil with iron (available from MeadJohnson & Company, Evansville, Ind., U.S.A.) may be supplemented with aneffective amount of sialic acid and used to practice the method of thepresent invention. Particular infant formulas suitable for use in thepresent invention are described in the Examples herein.

The total protein in the formulation from all protein sources should benutritionally appropriate for infants, which is typically from about 12g per liter to 18 g per liter and, in some embodiments, may be about 14g per liter. The total sialic acid in the formulation may be betweenabout 250 and about 1500 mg per liter and, in one embodiment, betweenabout 300 and about 600 mg per liter. The formulation may contain one ora combination of the following sialic acid-containing proteincomponents: (1) Up to 100% of the protein fraction from a whey proteinconcentrate, as commercially available from several sources includingDavisco, New Zealand Milk, or Formost Farms, exhibiting about 20-30 mgsialic acid per gram of protein and, thus, contributing between about140 and about 560 mg sialic acid per liter of formula; (2) up to 100% ofthe protein fraction from a nonfat dry milk product, as commerciallyavailable from several sources including New Zealand Milk, exhibitingabout 2-10 mg sialic acid per gram protein and, thus, contributingbetween about 27 and about 139 mg sialic acid per liter of formula; (3)up to 6 g per liter of casein glycomacropeptide (cGMP) or relatedprotein fraction, as commercially available from various sources,containing about 81% protein and between about 40 and about 300 mgsialic acid per gram of protein, but typically between about 40 and 60mg SA/gm protein, and, thus, contributing between about 194 and about1458 mg sialic acid per liter of formula, but typically between about194 and 290 mg SA/liter of formula; and (4) up to about 6 g/liter of acGMP fraction having an enhanced level of sialic acid.

When cGMP is employed, the casein glycomacropeptide may be extractedfrom milk using suitable processing. For example, the caseinglycomacropeptide may be extracted from the retentate obtained from theconcentration of whey protein. This may be done by at least partiallyremoving lactose from the retentate and then adding ethanol to causeprecipitation. The supernatant is then collected and dried to providethe casein glycomacropeptide. U.S. Pat. No. 5,216,129, which isincorporated herein entirely by reference to the extent that it does notconflict with information described herein, provides a more detaileddescription of this process. Alternatively, the cGMP may be purchasedfrom commercial sources such as, for example, The Tatua Co-OperativeDairy Company Limited, Tatuanui, Morrinsville, New Zealand, MD FoodsIngredients amba of DK-6920 Videbaek, Denmark or from DMV Internationalof NCB-laan 80, NL-5460 BA Veghel, The Netherlands.

It has been found that a preferred type of cGMP that is useful for thepresent compositions and methods is a cGMP-based product having anenhanced concentration of sialic acid. As used herein, the terms “cGMPhaving an enhanced concentration of sialic acid” mean a caseinglycomacropeptide (cGMP)-containing fraction of milk that has beentreated to increase the level of sialic acid, and in which the level ofsialic acid is higher, by any amount, than before the treatment. cGMPproducts with enhanced levels of sialic acid are described below inExamples 7 and 8.

One such product, an example of which is described in Example 7, can bereferred to herein as “cGMP having an enhanced level of sialic acid”, or“high-sialic acid cGMP”. High-sialic acid cGMP has a sialic acid contentof above about 60 mg/gm protein. It is preferred that the sialic acidcontent is above about 100 mg/gm protein, more preferred is above about150 mg/gm protein, and yet more preferred is a sialic acid content ofabove 200 mg/gm protein. Typically, this product has a protein contentof about 50%-60% by weight for a dry powder product, a sialic acidcontent of about 190-230 mg/gm protein, or about 100-130 mg/gm powder.In comparison, regular cGMP dry powder (for example, glycomacropeptideavailable from Tatua Co-Operative Dairy Company Limited) contains 81%protein by weight, and has a sialic acid content of about 52 mg/gmprotein, or 42 mg/gm powder. It is apparent, therefore, that the sialicacid content of the high-sialic acid cGMP has been enhanced over that ofthe regular glycomacropeptide powder by about 3-fold on the basis ofpowder weight, and about 4-fold on the basis of protein content of theproducts. For comparison purposes, electrodialyzed (ED) whey powdercontains about 14% protein on a dry basis, and contains about 30 mg ofsialic acid/gm protein, or about 4.3 mg of sialic acid/gm of powder.

An advantage of using a high-sialic acid cGMP as a protein source in aninfant formula is that the sialic acid content of the formula can beincreased without replacing an undue amount of the conventional sourcesof protein that are used in the formula. This feature is useful in thatit permits minimal disruption of the amino acid profile of the proteinof the formula.

In a particular embodiment of a high-sialic acid cGMP, the product has alevel of the amino acid threonine that is lower than the level of thatamino acid in the glycomacropeptide from which the novel product isderived. As used herein, this type of high-sialic acid cGMP is referredto as “cGMP having an enhanced level of sialic acid and reducedthreonine”, or “high-sialic acid cGMP with reduced threonine”. Anexample of this type of product is described below in Example 8.

High-sialic acid cGMP with reduced threonine has a sialic acid contentof above about 60 mg/gm protein and a threonine concentration that islower than about 15 gm/16 gm nitrogen. It is preferred that the sialicacid content is above about 100 mg/gm protein, more preferred is aboveabout 150 mg/gm protein, and yet more preferred is a sialic acid contentof above 200 mg/gm protein Typically, high-sialic acid cGMP with reducedthreonine can have a sialic acid content of from about 85 to about 150mg sialic acid (SA)/gram of powder, preferably from about 90 to about140 mg SA/g powder, which is comparable to the sialic acid content ofhigh-sialic acid cGMP. However, the threonine content of high-sialicacid cGMP with reduced threonine is only about one-fourth that of acommercial cGMP product. Preferably, the threonine content is belowabout 10 g/16 g nitrogen, more preferably below about 7 gm/16 gmnitrogen, even more preferably below about 5 g/16 g nitrogen, and yetmore preferably below about 4 g/16 g nitrogen. Expressed in analternative manner, the threonine content is below about 8% by weight ofthe total weight of amino acids of the protein, preferably below about6%, more preferably below about 4%, and yet more preferably below about3%.

An advantage provided by this type of enhanced sialic acid product isthat in addition to the increase in sialic acid with reduced amino acidprofile disruption, as discussed above, the threonine level of theprotein sources in the infant formula can be minimized. This isdesirable in some embodiments in order to reduce or eliminate thepotential for hyperthreoninuria, or other disorder caused by, orexacerbated by, high levels of threonine in the diet.

By way of example, an infant formula of the present invention can beformulated to have a sialic acid content of at least 200 mg/liter andhave a total protein content of between 12 and 16 grams/liter of whichno more than 40% by weight is provided by a cGMP having an enhancedconcentration of sialic acid. Preferably, such an infant formula has atotal protein content of between 13 and 15 grams/liter of which no morethan 30% by weight is provided by a cGMP having an enhancedconcentration of sialic acid, more preferably, the infant formula has atotal protein content of between 13 and 15 grams/liter of which no morethan 15% by weight is provided by a cGMP having an enhancedconcentration of sialic acid.

Also as an example, an infant formula of the present invention inventioncan be formulated to have a sialic acid content of at least 400 mg/literand have a total protein content of between 13 and 15 grams/liter ofwhich no more than 15% by weight is provided by a cGMP having anenhanced concentration of sialic acid.

The following examples describe exemplary embodiments of the invention.Other embodiments within the scope of the claims herein will be apparentto one skilled in the art from consideration of the specification orpractice of the invention as disclosed herein. It is intended that thespecification, together with the examples, be considered to be exemplaryonly, with the scope and spirit of the invention being indicated by theclaims which follow the examples. In the examples all percentages aregiven on a weight basis unless otherwise indicated.

EXAMPLE 1

This example illustrates the nutrient components in a commercial infantformula suitable for sialic acid addition for use in the presentinvention. TABLE 1 Nutrient Information for Infant Formula (Enfamil ®Lipil with Iron) NUTRIENTS Per 100 Calories (Normal Dilution) (5 fl oz)Protein, g 2.1 Fat, g 5.3 Carbohydrate, g 10.9 Water, g 134 Linoleicacid, mg 860 Vitamins: A, IU 300 D, IU 60 E, IU 2 K, μg 8 Thiamin(Vitamin B1), μg 80 Riboflavin (Vitamin B2), μg 140 B6, μg 60 B12, μg0.3 Niacin, μg 1000 Folic acid (Folacin), μg 16 Pantothenic acid, μg 500Biotin, μg 3 C (Ascorbic acid), mg 12 Choline, mg 12 Inositol, mg 16Minerals: Calcium, mg 78 Phosphorus, mg 53 Magnesium, mg 8 Iron, mg 1.8Zinc, mg 1 Manganese, μg 15 Copper, μg 75 Iodine, μg 10 Selenium, μg 2.8Sodium, mg 27 Potassium, mg 108 Chloride, mg 63

The ingredients of this particular formula are: reduced minerals whey,nonfat milk, vegetable oil (palm olein, soy, coconut, and high oleicsunflower oils), lactose, and less than 1%: mortierella alpina oil,crypthecodinium cohnii oil, vitamin A palmitate, vitamin D3, vitamin Eacetate, vitamin K1, thiamin hydrochloride, vitamin B6 hydrochloride,vitamin B12, niacinamide, folic acid, calcium pantothenate, biotin,sodium ascorbate, inositol, calcium chloride, calcium phosphate, ferroussulfate, zinc sulfate, manganese sulfate, cupric sulfate, sodiumchloride, sodium citrate, potassium citrate, potassium hydroxide, sodiumselenite, taurine, nucleotides (adenosine 5′-monophosphate, cytidine5′-monophosphate, disodium guanosine 5′-monophosphate, disodium uridine5′-monophosphate).

To use this particular formula to practice the present invention, itwould be necessary to add, for example, from about 250 mg per liter toabout 1500 mg per liter of sialic acid-containing ingredients to thecomposition described in Table 1. This added amount of sialic acid wouldbe part of the total amount of protein (total protein of approximately2.1 grams per 100 calories).

EXAMPLE 2

This example illustrates a particular protein source combination for atotal sialic acid content of approximately 250 mg per liter. Theingredients listed in Table 2 would be used to replace the proteincomponent of the formula described in Table 1. TABLE 2 Protein SourceComposition A mg SA/ % of gm protein in g g mg Ingredient proteiningredient ingredient/L protein/L SA/L Whey Protein 23.00 35.00 20.267.09 163.08 Concentrate Nonfat Dry 6.37 34.00 15.38 5.23 33.31 Milk, LowHeat cGMP 52.00 81.00 1.45 1.17 61.07Note“SA” in table means sialic acid.

EXAMPLE 3

This example illustrates a particular protein source combination for atotal sialic acid content of approximately 360 mg per liter. Theingredients listed in Table 3 replace the protein component of theformula described in Table 1. TABLE 3 Protein Source Composition B mgSA/ % of gm protein in g g mg Ingredient protein ingredient ingredient/Lprotein/L SA/L Whey Protein 23.00 35.00 37.00 12.95 297.85 ConcentratecGMP 52.00 81.00 1.45 1.17 61.07Note“SA” in table means to sialic acid

EXAMPLE 4

This example illustrates a particular protein source combination for atotal sialic acid content of approximately 600 mg per liter. Theingredients listed in Table 4 replace the protein component of theformula described in Table 1. TABLE 4 Protein Source Composition B mgSA/ % of gm protein in g g mg Ingredient protein ingredient ingredient/Lprotein/L SA/L Whey Protein 23.00 35.00 13.00 4.55 104.65 ConcentratecGMP 52.00 81.00 12.00 9.72 505.44NoteSA in table refers to sialic acid

EXAMPLE 5

Table 5 illustrates one possible complete nutritional formulation of aninfant formula with a total sialic acid content of approximately 250 mgper liter. TABLE 5 Exemplary infant formulation with sialic acid. Amountper Ingredient Weight 10000 liters Lactose (95% Solids) 573.000 kg FatBlend 332.500 kg Whey Protein Concentrate (36% Protein, 5.8% Ash)202.578 kg Nonfat Milk Solid (36% Prot., 52% CHO) 153.844 kg CaseinoGlyco Macro Peptides (cGMP, 81.18% Prot.) 14.500 kg Mono-andDiglycerides 7.233 kg Calcium Phosphate, Tribasic 6.520 kg Single CellArachidonic Acid Oil 6.485 kg Dry Vitamin Premix for Enfamil AR Liquid5.250 kg   Ascorbic Acid 2924.250 g   Inositol 834.750 g   Corn SyrupSolid 654.938 g   Taurine 582.750 g   Niacinamide 119.438 g   CalciumPantothenate 44.730 g   Vitamin B12, 0.1% in Starch 29.400 g   Biotin,1% Trituration 25.095 g   Thiamine Hydroxhloride 13.913 g   Riboflavin10.238 g   Pyridoxine Hydrochloride 8.138 g   Folic Acid 2.363 gLecithin Concentrate 3.694 kg Potassium Citrate 3.350 kg Single CellDocosahexaenoic Acid Oil 3.243 kg Nucleotide Premix for Enfamil Powder2.900 kg   Maltodextrin, 15 DE 2552.290 g   Cytidine 5′-monophosphate,free acid 202.710 g   Uridine 5′-monophosphate, disodium salt 59.740 g  Adenosine 5′-monophosphate, free acid 47.357 g   Guanosine5′-monophosphate, disodium salt 37.903 g Carrageenan 2.826 kg MagnesiumChloride 1.657 kg Calcium Chloride, Dihydrate 1.200 kg Choline Chloride0.700 kg Ferrous Sulfate Heptahydrate 0.682 kg Sodium Citrate,Dihydrate, Granular 0.455 kg Trace Mineral Premix w/Selenite Trituration0.392 kg   Zinc Sulfate, Monohydate 276.238 g   Sodium SeleniteTrituration, 0.5% 65.907 g   Cupric Sulfate, powder 29.510 g   Lactose,Grind A 16.323 g   Manganese Sulfate, monohydrate 4.022 g Vitamin A, D,E, K Premix, Enfamil Liquid 0.324 kg   Tocopherol Acetate 160.882 g  Soybean Oil 139.612 g   Vitamin A Palmitate 17.253 g   CholecalciferolConcentrate 5.715 g   Vitamin K1, Liquid 0.538 g Ascorbic Acid 0.150 kgL-Carnitine 0.150 kg Water, Defluoridated, q.s. to 10310.986 kgPotassium Hydroxide —

Table 6 and Table 7 detail the content of specific components of theformulation described in Table 5 as a percentage of 1) weight to weight,2) weight to volume, and 3) calories. The specific gravity of thisparticular formulation is 1.0310986. TABLE 6 Infant formulationcomposition. Component % w/w % w/v Protein 1.38 1.42 Fat 3.50 3.61Carbohydrate 7.20 7.43 Ash 0.37 0.38 Total Solids 12.45 12.84

TABLE 7 Infant formula caloric distribution Component % Protein 8.38 Fat47.83 Carbohydrate 43.79

EXAMPLE 6

Table 8 illustrates the nutritional content of the formulation presentedin Example 5 per 100 calories, as well as per 100 milliliters offormula. TABLE 8 Nutritional content of infant formulation. Per 100 CalPer 100 ml Calories, Cal 100 68 Protein, g 2.1 1.42 Fat, g 5.3 3.6Carbohydrate, g 10.9 7.4 Linoleic Acid, mg 860 580 Linolenic Acid, mg 8054 Arachidonic Acid, mg 34 23 Docosahexaenoic Acid, mg 17 11.5 VitaminA, IU 300 200 Vitamin D, IU 60 41 Vitamin E, IU 2 1.35 Vitamin K1, mcg12 8.1 Thiamin, mcg 120 81 Riboflavin, mcg 140 95 Vitamin B6, mcg 60 41Vitamin B12, mcg 0.5 0.3 Niacin, mcg 1200 812 Folic Acid, mcg 16 10.8Pantothenic Acid, mcg 500 340 Biotin, mcg 3 2 Vitamin C, mg 14 9.5Choline, mg 12 8.1 Inositol, mg 6 4.1 Taurine, mg 6 4.1 L-Carnitine, mg2 1.35 Calcium, mg 78 53 Phosphorus, mg 53 36 Magnesium, mg 8 5.4 Iron,mg 1.8 1.2 Zinc, mg 1 0.68 Manganese, mcg 26 17.6 Copper, mcg 85 57Iodine, mcg 15 10 Sodium, mg 27 18.3 Potassium, mg 108 73 Chloride, mg63 43 Selenium, mcg 2.8 1.89 Sialic acid, mg 37 25 Calcium/PhosphorusRatio — — AMP Equivalents, mg (a) 0.5 0.34 CMP Equivalents, mg (a) 2.51.69 GMP Equivalents, mg (a) 0.3 0.20 UMP Equivalents, mg (a) 0.9 0.61Nucleotide Equivalents, mg (a) 4.2 2.84 TPAN-AMP, mg — — TPAN-CMP, mg —— TPAN-GMP, mg — — TPAN-UMP, mg — — Total TPAN, mg — — TPAN-CMP/TPAN-GMPRatio — —

EXAMPLE 7

This illustrates the production of a cGMP product having enhanced levelsof sialic acid.

A fraction of cheese whey that is enriched in GMP is fractionated byusing anion chromatography to yield a fraction that is enhanced insialic acid. This product exhibits an amino acid profile similar to thatof currently commercially available GMP (available from TatuaCo-Operative Dairy Company Limited, Tatuanui, Morrinsville, NewZealand), but contains from 1.5-3 times the sialic acid content ofcurrently available GMP products.

The sialic acid-enhanced fraction can be desalted, if desired, byelectrodialysis, for example, and can be dried to yield a dry powderproduct, which is then useable for introduction into a liquid or a dryinfant formula mix. This product is a high-sialic acid cGMP and isavailable as of the filing date of the present application from TatuaCo-Operative Dairy Company Limited, as products designated as X4738,X4739, X4740, and X4741. The protein content, sialic acid content, andamino acid profile of those materials is described in Table 9. TABLE 9Amino acid profile and sialic acid content of four examples ofhigh-sialic acid cGMP products. High-Sialic Acid cGMP Product Samples EDWhey Amino Acid X4738 X4739 X4740 X4741 Average cGMP Powder Powderarginine 1.22 0.96 0.69 0.7 0.89 1.4 histidine 0.76 0.7 0.59 0.59 0.66 1isoleucine 10.36 8.42 11.28 11.51 10.39 11.6 leucine 4 3.36 3.19 3.213.44 4.6 lysine 7.48 7.91 6.89 7.08 7.34 8.3 methionine 2 2.04 1.63 1.631.83 1.5 cystine 0.21 0.47 0.13 0.09 0.23 0.2 phenylalanine 1.54 5.881.96 2.08 2.87 1.8 tyrosine 0.35 0.17 0.1 0.09 0.18 0.4 threonine 13.1315.16 17.18 17.57 15.76 15.9 tryptophan 0 0 0 0 0.00 0 valine 8.69 7.559.38 9.51 8.78 9.7 alanine 6.8 6.58 6.41 6.53 6.58 6.6 aspartic acid10.61 12.12 9.93 10 10.67 11.1 glutamic acid 22.91 24.23 23.28 23.1423.39 26.2 glycine 1.37 1.46 1.31 1.34 1.37 1.5 proline 11.13 10.1910.78 9.57 10.42 14.2 serine 8.14 9.66 8.74 9.06 8.90 8.1 TOTAL 110.7116.86 113.47 113.7 113.68 124.1 % protein 51.88 49.92 57.87 60.05 54.9381 14.31 mgSA/gm 188.43 227.25 224.83 215.68 214.05 52 29.92 proteinmgSA/gm 97.76 113.44 130.11 129.52 117.71 42.12 4.28 powder AverageAmino acid levels are expressed as grams of the amino acid per 16 gramsof nitrogen.cGMP Powder is commercial glycomacropeptide from Tatua Co-OperativeDairy Company Ltd.ED Whey Powder is commercial electrodialyzed whey powderSamples X4738-X4741 are samples of high-sialic acid cGMP available fromTatua Co-Operative Dairy Company Limited, Tatuanui, Morrinsville, NewZealand.

EXAMPLE 8

This illustrates the production of a cGMP product having enhanced levelsof sialic acid and low levels of threonine.

A fraction of cheese whey that is enriched in GMP is subjected to apartial proteolytic hydrolysis followed by fractionation by using anionchromatography to yield a fraction that is enhanced in sialic acid andhas a low threonine content. This product contains from 1.5-3 times thesialic acid content of currently available GMP products, but the levelof threonine is reduced to about one-fourth that of the starting GMPmaterial.

The sialic acid-enhanced, low threonine fraction can be desalted, ifdesired, by electrodialysis, for example, and can be dried to yield adry powder product, which is then useable for introduction into a liquidor a dry infant formula mix. This product is a high-sialic acid cGMPwith reduced threonine and is available as of the filing date of thepresent application from Tatua Co-Operative Dairy Company Limited,Tatuanui, Morrisnville, New Zealand, as product designated as W4733. Theprotein content, sialic acid content, and amino acid profile of thatmaterial is described in Table 10. TABLE 10 Amino acid profile andsialic acid content of high-sialic acid cGMP with reduced threonine.High-Sialic Acid cGMP with Reduced Threonine cGMP ED Whey Amino AcidW4733 Powder Powder arginine 2.3 1.4 histidine 0 1 isoleucine 13.1 11.6leucine 5.3 4.6 lysine 3.2 8.3 methionine 0.7 1.5 cystine 0.1 0.2phenylalanine 0 1.8 tyrosine 0 0.4 threonine 3.8 15.9 tryptophan 0 0valine 16.3 9.7 alanine 15.9 6.6 aspartic acid 6.3 11.1 glutamic acid38.9 26.2 glycine 2.5 1.5 proline 16.9 14.2 serine 0 8.1 TOTAL 125.4124.1 % protein 81 14.31 mgSA/gm protein 52 29.92 mgSA/gm powder 138.0342.12 4.28 (Repeat analysis) 117.02 Average 127.525Amino acid levels are expressed as grams of the amino acid per 16 gramsof nitrogencGMP Powder is commercial glycomacropeptide from Tatua Co-OperativeDairy Company Ltd.ED Whey Powder is commercial electrodialyzed whey powderSamples W4731, W4733, and W4735 are samples of enhanced sialic acid cGMPwith reduced threonine available from Tatua Co-Operative Dairy CompanyLimited, Tatuanui, Morrinsville, New Zealand.

It is noted that the threonine level of the novel product are aboutone-fourth that of commercial cGMP. Accordingly, it is believed that useof a high-sialic acid cGMP with reduced threonine in an infant formulacan provide a formula having a high level of sialic acid at normal,desirable protein levels of about 14 g protein/liter, and yet provide adesirable amino acid profile and low levels of threonine.

EXAMPLE 9

This illustrates the use of a cGMP fraction having enhanced levels ofsialic acid in an infant formula.

The cGMP product having enhanced levels of sialic acid can be used as aprotein source in an infant formula in the same manner as a whey powderor normal cGMP powder. By way of example, Table 11 shows the sialic acidcontent that could be expected for an infant formula in which theprotein content is supplied by conventional sources. The amount of cGMPpowder that is used is limited in order to avoid undue deviation of theamino acid profile of the protein that is provided from a desirableinfant standard profile. TABLE 11 Sialic acid content of infant formulawith protein provided by conventional sources: mg sialic acid/ Percentgrams mg sialic Protein Source gm protein protein protein/literacid/liter Whey protein 23 35% 6.82 156.77 concentrate Nonfat dry milk,6.37 34% 6.25 39.8 low heat cGMP Powder 52 81% 1.11 57.62 Total 14.17254.18

The cGMP powder that is used in this formulation can be replaced bynovel cGMP product having an enhanced level of sialic acid, as isdescribed above in EXAMPLE 7. Table 12 shows that when this is done, thesialic acid content of the formulation is more than doubled with nofurther disruption of the amino acid profile of the protein. TABLE 12Sialic acid content of infant formula with protein provided byconventional sources plus a cGMP product having an enhanced level ofsialic acid: mg sialic acid/ Percent grams mg sialic Protein Source gmprotein protein protein/liter acid/liter Whey protein 23   35% 6.82156.77 concentrate Nonfat dry milk, 6.37   34% 6.25 39.8 low heat cGMPProduct 214 54.93% 1.11 237.54 with enhanced sialic acid Total 14.17434.12

If the cGMP powder having enhanced sialic acid levels were to be used atdouble the levels described above at the expense of nonfat dry milk, thesialic acid content of the formula could be increased to the level shownin Table 13. TABLE 13 Sialic acid content of infant formula with proteinprovided by conventional sources plus a cGMP product with an enhancedlevel of sialic acid: mg sialic acid/ Percent grams mg sialic ProteinSource gm protein protein protein/liter acid/liter Whey protein 23   35%6.82 156.77 concentrate Nonfat dry milk, 6.37   34% 5.14 32.74 low heatcGMP Product 214 54.93% 2.22 475.08 with enhanced sialic acid Total14.18 664.59

These and other modifications and variations to the present inventionmay be practiced by those of ordinary skill in the art, withoutdeparting from the spirit and scope of the present invention, which ismore particularly set forth in the appended claims. In addition, itshould be understood that aspects of the various embodiments might beinterchanged both in whole and in part. Furthermore, those of ordinaryskill in the art will appreciate that the foregoing description is byway of example only, and is not intended to limit the invention sofurther described in such appended claims. Therefore, the spirit andscope of the appended claims should not be limited to the description ofthe preferred versions contained therein.

All references cited in this specification, including without limitationall papers, publications, patents, patent applications, presentations,texts, reports, manuscripts, brochures, books, internet postings,journal articles, periodicals, and the like, are hereby incorporated byreference into this specification to the extent that they do notconflict with the disclosure of this specification. The discussion ofthe references herein is intended merely to summarize the assertionsmade by their authors and no admission is made that any referenceconstitutes prior art. Applicants reserve the right to challenge theaccuracy and pertinency of the cited references.

1. An infant formula comprising cGMP having an enhanced concentration ofsialic acid.
 2. The infant formula according to claim 1, having a sialicacid level of at least about 200 mg/liter.
 3. The infant formulaaccording to claim 1, having a sialic acid level of at least about 250mg/liter.
 4. The infant formula according to claim 1, having a sialicacid level of at least about 300 mg/liter.
 5. The infant formulaaccording to claim 1, having a sialic acid level of at least about 400mg/liter.
 6. The infant formula according to claim 1, having a sialicacid level of at least about 600 mg/liter.
 7. The infant formulaaccording to claim 1, having a total protein content of between 12 and16 grams/liter of which no more than 40% by weight is provided by a cGMPhaving an enhanced concentration of sialic acid.
 8. The infant formulaaccording to claim 1, having a total protein content of between 13 and15 grams/liter of which no more than 30% by weight is provided by a cGMPhaving an enhanced concentration of sialic acid.
 9. The infant formulaaccording to claim 1, having a total protein content of between 13 and15 grams/liter of which no more than 15% by weight is provided by a cGMPhaving an enhanced concentration of sialic acid.
 10. The infant formulaaccording to claim 3, having a total protein content of between 13 and15 grams/liter of which no more than 30% by weight is provided by a cGMPhaving an enhanced concentration of sialic acid.
 11. The infant formulaaccording to claim 4, having a total protein content of between 13 and15 grams/liter of which no more than 30% by weight is provided by a cGMPhaving an enhanced concentration of sialic acid.
 12. The infant formulaaccording to claim 5, having a total protein content of between 13 and15 grams/liter of which no more than 30% by weight is provided by a cGMPhaving an enhanced concentration of sialic acid.
 13. The infant formulaaccording to claim 1, wherein the cGMP having an enhanced concentrationof sialic acid comprises high-sialic acid cGMP with reduced threonine.14. The infant formula according to claim 13, having a sialic acid levelof at least about 250 mg/liter.
 15. The infant formula according toclaim 13, having a sialic acid level of at least about 300 mg/liter. 16.The infant formula according to claim 13, having a sialic acid level ofat least about 400 mg/liter.
 17. The infant formula according to claim13, having a sialic acid level of at least about 600 mg/liter.
 18. Theinfant formula according to claim 13, having a total protein content ofbetween 12 and 16 grams/liter of which no more than 40% by weight isprovided by a cGMP having an enhanced concentration of sialic acid. 19.The infant formula according to claim 13, having a total protein contentof between 13 and 15 grams/liter of which no more than 30% by weight isprovided by a cGMP having an enhanced concentration of sialic acid. 20.The infant formula according to claim 13, having a total protein contentof between 13 and 15 grams/liter of which no more than 15% by weight isprovided by a cGMP having an enhanced concentration of sialic acid. 21.The infant formula according to claim 14, having a total protein contentof between 13 and 15 grams/liter of which no more than 30% by weight isprovided by a cGMP having an enhanced concentration of sialic acid andhaving a threonine content of not over 10 grams/16 grams nitrogen. 22.The infant formula according to claim 15, having a total protein contentof between 13 and 15 grams/liter of which no more than 30% by weight isprovided by a cGMP having an enhanced concentration of sialic acid andhaving a threonine content of not over 7 grams/16 grams nitrogen. 23.The infant formula according to claim 16, having a total protein contentof between 13 and 15 grams/liter of which no more than 30% by weight isprovided by a cGMP having an enhanced concentration of sialic acid andhaving a threonine content of not over 4 grams/16 grams nitrogen. 24.The infant formula according to claim 13, having a total protein contentof about 14 grams/liter of which not over 4% by weight is threonine andhaving a sialic acid content of at least 400 mg/liter.
 25. A method ofproducing an infant formula comprising intermixing a cGMP having anenhanced concentration of sialic acid with sources of protein,carbohydrate and lipid sufficient to provide a nutritionally completeformula.